Black hair doesn't know how to study hard early, and white hair regrets learning late.

It is difficult for young people to learn and grow old, and an inch of time is not light.

If a person doesn't work hard when he is young, he will regret when he is old ―― laziness when he is young will make him regret when he is old; Reckless youth makes regretful old age; Idle youth, poor old age

Time is life, wasting other people's time for no reason is tantamount to killing people for money. -Lu Xun

It's hard to get up in the morning if you don't come back in your prime; It's time for people to encourage themselves when they reach middle age. Time goes by and waits for no one.